<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            height: 2000px;
        }
        
        .pic {
            position: fixed;
            right: 30px;
            bottom: 30px;
        }
    </style>
</head>

<body>
    <div class="box">这是一个大盒子</div>
    <div class="pic"><img src="./img/sprite@2x.png" alt="" srcset=""></div>
</body>

</html>